We get a handful of the cheapy ones from the local drug stores/dollar stores to wear while on water attractions. Since they're cheap we hand them off to folks who don't have them heading into line if they didn't rip too badly during our ride. Otherwise, if you know it's going to rain all week, I'm throwing in another vote for the Disney ponchos. Durable, decent protection, and fully replaced if they do happen to rip during your stay. (Keep the receipt).